Lateral-reading compass



Nov. 26, 1929. E P. G WUNSCH I 1,737,487

LATERAL READING COMPASS Filed Dec. 8, 1927 y* U D .V u n v (j A u u A u A 2%@ Patentedl Nov. 26, 1929 UNITED STATES PATENT oEElcE ERICH PAUL eUizno wNscII, or sTEGLITz, NEAR BERLIN, GERMANYS AssIGNoR 'ro AsKANIA-WERKE A.G. voRMALs CENTRALWERKSTAT'I DESSAU UND CARI. BAM- BERG-FRIEDENAU, oF BERLIN-ERIEDENAU, GERMANY, A CORPORATION oF GER- MANY LATERAEREADING coMPAss Application led December 8, 1927, Serial No.

` 5 side of the compass and not as in the ordinary compass from above. It is known that for 'the purpose of steering aircraft, it is of the highest importance that the pilot should be able to see by a glance at the compass that l he is steering a correct course, without'havingvto read the angle of the course steered. It has already been proposed for the above purpose to arrange on the compass card a separate course 4indicator which, after setting to the desired angle of steering, could be coupled to the compass card, and which, if the correct course is kept, must coincide with the lubbers 'line of the compass. Such an arrangement is however only possible in Compasses with a compass card arranged horizontally above the compass bowl.

According to the present invention there is provided a separate course or steering card which is provided with a scale divided into degrees corresponding to the scale of the compass card, and has moreover, at one or more points of the circumference, conspicuous, easily recognizable marks to which correspond similar marks onvthe compass card. The course .or steering card can be set by means of a setting screw or the like arranged outside the compass bowl, opposite the lubbers line to the steering angle desired, so that the pilot when steering or navigating the aircraft has merely to see that the marks provided on the steering card coincide withthe marks on the compass card.

The marks are preferably arranged at the four cardinal points of the steering card and of the compass card, in the form of triangular recesses, arrows or the like, the points of which face each other and stand out clearly from the surface of` the cards and from'the back-ground. e

The accompanying drawing shows by way of example, in front of elevation, a fluid compass according to the invention for aircraft.

The compass lbody consists essentially of the outer compass-case a of substantially hemispherical shape in which is arranged a 238,569, and in Germany December 10, 1926.

houw bau b madenf glass and sued with i a sultable liquid. The compass case a is rotatably mounted in a bracket c provided with a bed plate d and can be locked in a given p osition by means of a screw e. In the interior of the hollow ball b is mounted in a well known manner on a pin g a compass .card f. Above the compass card f is arranged a .card 71l of exactly or approximately the same diameter for setting the course, which card is secured by means of a number of arms i to a vertical spindle'k passing at tle top through the case a. The spindlelc is mounted at its upper end in the cover m vof a'cylindrical superstructure n of the case a forming a part of the compass body `and has a bevel wheel o which meshes with a second. bevel wheel g mounted on a horizontal spindle p. To the end ofthe spindlel p which projects from the superstructure n, is secured a setting button 1", by turning which, the steering-card l1, can be adjusted-in any desired manner. Over the compass card f and the steering card h extends a lubbers line constituted by like, the upper end of which extends obliquely towards the axis of the compass andis secured to a ,sleeve t enclosing the. spindle ls. The compass card f is displaced 180 from the usual arrangement, that is, the north-seeking pole o f the needle is adjacent/the S graduation. This arrangement is necessar as the lubbers line s is arrangedonthe ront side of the compass case, i. e. on the side on which the pilot is standing. The sleeve t carr1es at its upper end a lateral projection u which is connected by a pin v to the cover m of the casing superstructure n. By turning the cover mit is therefore possible to Set the lubbers line s in-a Well yknown manner.

The steering card It is provided with a scale corresponding to the degree divisions of the compass card fnamely the degree numbering, and the scale divisionsf the steering card L as well as `those of the compass card f, are

a Wire s, or the I cards 72, and f, are further stamped out large triangular recesses :v and lw the points of which face each other.v The recesses a: reach with their points approximately right 'up to the upper edge of the compass card f, whilst the recesses 'w extend from the lower edge of the steering cards 7L provided at L,the corresponding point with corresponding triangular points, close to the upper edge of the compass card j. 'Ihe making of the degree numl bers and scale divisions or strokes by stamping out the cards, aswell as the arrangement of the triangular recesses 'w and has besides the advantage of clearness. the further advantage of reducing the inertia.

Whenf using the compass, the course to be kept is set at the lubbers line s by turning the steering card k by means of the button 1'. After that, when steering, it is no longer necessary to watch the lubbers line or to read the steering angle, the pilot has merely to see that the recesses ofthe compass card f, clearly visible at a glance, are opposite the Corresponding recesses fw of the steering card l n The invention is not. limited of course to the construction shown but can be applied in the same or similar way to Compasses of any other desired kind.

Having now particularly described and asv certained the nature of my said invention and in what manner the same is to be performed,

I declare that what I claim is 1. In a lateral-reading compass, 'a sub-" stantially cylindrical compass card having direction-indicia on its periphery, a similar substantially cylindrical indicator similarly marked and rotatably mounted concentric with the axis of said card adjacent thereto,

a lubbers line for reading both-the card and` indicator, and means for rotating the indicator to set a desired course in cooperation with the lubbers line.

2. A compass as per claim 1 wherein said card and indicator are sections ofthe surface of a sphere cut off by four adjacent parallel planes. A'

3. A compass asrper claim 1 wherein the direction-indicia at the corresponding cardinal points of both cards consist of marks of triangular shape having their points facingl each other.

4. A compass as per claim 1 wherein the direction-indicia at the corresponding cardinal points of both cards consist of marks of triangular sha e havin their points facing each other an the card rim. i

In testimony whereof `I have aiixed my signature.

ERICH PAUL-,GUIDO WUN' SCH.

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